From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 783ABC7618F for ; Tue, 16 Jul 2019 18:43:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 62D602064B for ; Tue, 16 Jul 2019 18:43:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388294AbfGPSns (ORCPT ); Tue, 16 Jul 2019 14:43:48 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:39402 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728190AbfGPSnr (ORCPT ); Tue, 16 Jul 2019 14:43:47 -0400 Received: from pps.filterd (m0098394.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x6GIbNPC014456; Tue, 16 Jul 2019 14:41:23 -0400 Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com with ESMTP id 2tshy55vjw-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 16 Jul 2019 14:41:22 -0400 Received: from m0098394.ppops.net (m0098394.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.27/8.16.0.27) with SMTP id x6GIfMS8050544; Tue, 16 Jul 2019 14:41:22 -0400 Received: from ppma01wdc.us.ibm.com (fd.55.37a9.ip4.static.sl-reverse.com [169.55.85.253]) by mx0a-001b2d01.pphosted.com with ESMTP id 2tshy55vhk-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 16 Jul 2019 14:41:22 -0400 Received: from pps.filterd (ppma01wdc.us.ibm.com [127.0.0.1]) by ppma01wdc.us.ibm.com (8.16.0.27/8.16.0.27) with SMTP id x6GIdjf0027347; Tue, 16 Jul 2019 18:41:20 GMT Received: from b01cxnp22034.gho.pok.ibm.com (b01cxnp22034.gho.pok.ibm.com [9.57.198.24]) by ppma01wdc.us.ibm.com with ESMTP id 2tq6x618hu-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 16 Jul 2019 18:41:20 +0000 Received: from b01ledav003.gho.pok.ibm.com (b01ledav003.gho.pok.ibm.com [9.57.199.108]) by b01cxnp22034.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x6GIfKf944630514 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 16 Jul 2019 18:41:20 GMT Received: from b01ledav003.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id ECC48B2067; Tue, 16 Jul 2019 18:41:19 +0000 (GMT) Received: from b01ledav003.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id AA33DB2068; Tue, 16 Jul 2019 18:41:19 +0000 (GMT) Received: from paulmck-ThinkPad-W541 (unknown [9.80.225.134]) by b01ledav003.gho.pok.ibm.com (Postfix) with ESMTP; Tue, 16 Jul 2019 18:41:19 +0000 (GMT) Received: by paulmck-ThinkPad-W541 (Postfix, from userid 1000) id B8B1116C8E9B; Tue, 16 Jul 2019 11:41:19 -0700 (PDT) Date: Tue, 16 Jul 2019 11:41:19 -0700 From: "Paul E. McKenney" To: "Joel Fernandes (Google)" Cc: linux-kernel@vger.kernel.org, Alexey Kuznetsov , Bjorn Helgaas , Borislav Petkov , c0d1n61at3@gmail.com, "David S. Miller" , edumazet@google.com, Greg Kroah-Hartman , Hideaki YOSHIFUJI , "H. Peter Anvin" , Ingo Molnar , Jonathan Corbet , Josh Triplett , keescook@chromium.org, kernel-hardening@lists.openwall.com, kernel-team@android.com, Lai Jiangshan , Len Brown , linux-acpi@vger.kernel.org, linux-doc@vger.kernel.org, linux-pci@vger.kernel.org, linux-pm@vger.kernel.org, Mathieu Desnoyers , neilb@suse.com, netdev@vger.kernel.org, Oleg Nesterov , Pavel Machek , peterz@infradead.org, "Rafael J. Wysocki" , Rasmus Villemoes , rcu@vger.kernel.org, Steven Rostedt , Tejun Heo , Thomas Gleixner , will@kernel.org, "maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" Subject: Re: [PATCH 6/9] workqueue: Convert for_each_wq to use built-in list check (v2) Message-ID: <20190716184119.GH14271@linux.ibm.com> Reply-To: paulmck@linux.ibm.com References: <20190715143705.117908-1-joel@joelfernandes.org> <20190715143705.117908-7-joel@joelfernandes.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190715143705.117908-7-joel@joelfernandes.org> User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-07-16_04:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1907160228 Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Mon, Jul 15, 2019 at 10:37:02AM -0400, Joel Fernandes (Google) wrote: > list_for_each_entry_rcu now has support to check for RCU reader sections > as well as lock. Just use the support in it, instead of explictly > checking in the caller. > > Signed-off-by: Joel Fernandes (Google) We need an ack from one of the subsystem maintainers on this one. Thanx, Paul > --- > kernel/workqueue.c | 10 ++-------- > 1 file changed, 2 insertions(+), 8 deletions(-) > > diff --git a/kernel/workqueue.c b/kernel/workqueue.c > index 601d61150b65..e882477ebf6e 100644 > --- a/kernel/workqueue.c > +++ b/kernel/workqueue.c > @@ -364,11 +364,6 @@ static void workqueue_sysfs_unregister(struct workqueue_struct *wq); > !lockdep_is_held(&wq_pool_mutex), \ > "RCU or wq_pool_mutex should be held") > > -#define assert_rcu_or_wq_mutex(wq) \ > - RCU_LOCKDEP_WARN(!rcu_read_lock_held() && \ > - !lockdep_is_held(&wq->mutex), \ > - "RCU or wq->mutex should be held") > - > #define assert_rcu_or_wq_mutex_or_pool_mutex(wq) \ > RCU_LOCKDEP_WARN(!rcu_read_lock_held() && \ > !lockdep_is_held(&wq->mutex) && \ > @@ -425,9 +420,8 @@ static void workqueue_sysfs_unregister(struct workqueue_struct *wq); > * ignored. > */ > #define for_each_pwq(pwq, wq) \ > - list_for_each_entry_rcu((pwq), &(wq)->pwqs, pwqs_node) \ > - if (({ assert_rcu_or_wq_mutex(wq); false; })) { } \ > - else > + list_for_each_entry_rcu((pwq), &(wq)->pwqs, pwqs_node, \ > + lock_is_held(&(wq->mutex).dep_map)) > > #ifdef CONFIG_DEBUG_OBJECTS_WORK > > -- > 2.22.0.510.g264f2c817a-goog >